Manufacture of bunched wire



April 7, 1970 S. R. SANTER MANUFACTURE OF BUNCHED WIRE Filed March 20, 1968 2 Sheets-Sheet 1 I rwentor SIDNEY RICHARD SANTER Home April 7, 1970 s. R. SANTER 3,504,487

MANUFACTURE OF BUNCHED WIRE Filed March 20, 1968 2 Sheets-Sheet 2 I nuenlor SIDNEY RICHARD SANTER United States Patent 3,504,487 Patented Apr. 7, 1970 3,504,487 MANUFACTURE OF BUNCHED WIRE Sidney Richard Santer, West Moors, Dorset, England, assignor to B. & F. Carter & Co. Limited, Bolton, Lancashire, England Filed Mar. 20, 1968, Ser. No. 714,479 Claims priority, application Great Britain, Mar. 22, 1967, 13,548/ 67 Int. Cl. D02g 3/36; D01h 7/02; D07b 3/02 US. Cl. 57-12 11 Claims ABSTRACT OF THE DISCLOSURE In the manufacture of bunched strand (especially of 100 or more fine wires) by means of a double-twist bunching machine, the material is fed into the machine as a bunch rotating about its own axis faster than the speed of rotation of the fiyer of the machine, preferably twice as fast. An endless belt haul-off that rotates about the axis of the bunch can be used to draw the wires from stationary supply reels and feed them as a rotating bunch into the bunching machine.

This invention relates to a method of and apparatus for twisting together a plurality of elongated flexible elements to form a bunched strand by means of a double twisting bunching machine.

Fine wire strand is commonly produced by drawing a plurality of wires from a group of bobbins, each mounted for rotation about its axis on a stationary stand, and bringing the wires together to form a bunch to which twist is imparted by means of a double twist bunching machine comprising essentially a take-up for the twisted bunch of wires and a flyer which is rotatably driven about the take-up and conveys the bunched wires first axially forwards and then in a loop rotating around the take-up (which normally remains stationary in space) and then axially rearwards towards the take-up. Such machines impart a twist of 720 to the bunch wires during each complete revolution of the flyer of the bunching machine relative to the take-up when it is stationary in space, onehalf of this twist being put in at the entry end of the fiyer and the other half at the delivery end of the flyer.

Machines of this kind are relatively cheap as compared with tubular stranding machines in which the supply bobbins are mounted in a rotating tube or tubes and the stranded conductor is drawn off from the closing die by a capstan located at the front end of the tube and thence fed to a take-up reel. Double twist bunching machines are capable of producing technically satisfactory bunched strands when the number of components is not large but difiiculties are encountered in attempting to produce heavy fine wire strand, that is to say strand formed of at least one hundred fine .wires, for example over two hundred wires, by means of a double twist bunching machine.

This difficulty arises from the fact that in a given length of strand the length of the individual wires will vary according to the positions they occupy in the strand. With tubular stranders and single twist bunching machines there is no difliculty as the wires are automatically drawn off their respective supply bobbins at correspondingly slightly different rates. In the case of a double twist bunching machine this is possible only with respect to the first twisting stage. Between that stage and the second twisting stage the .wires are locked together and twisting in the second stage can only result in the stretching of the outer wires of the strand or in an excess length of wire in the inner wires of the strand. The former is obviously undesirable; the latter can result in surplus wire being forced outwards from the interior of the strand.

An object of the present invention is to provide an improved method of and apparatus for the manufacture of heavy fine Wire bunched strand which avoid the difliculties introduced by the usual double twist bunching machine and yet possess to a large extent the simplicity and economy of existing methods of, and machines for, double twist bunching.

In the method in accordance with the invention, the elements (hereinafter referred to as wires) are brought together and formed into a twisted bunch by rotating the longitudinally advancing bunch of wires about a rectilinear axis within the bunch and then fed into a double twist bunching machine whose flyer is driven in rotation in the same direction as but at a speed less than the speed of rotation of the longitudinally advancing bunch to the extent that at least a substantial proportion of and preferably all of the twist present in the finished strand taken up in the bunching machine is put in prior to its entry into the bunching machine i.e. at a stage where the differences in lengths of individual wires are compensated for by the dilfering rates of draw-off from their supply devices. If, as is preferred, the speed of rotation of the flyer is half that of the bunch at entry into the bunching machine and the take-up is stationary in space, the sole effect of the double twist bunching machine is first to take out half the twist in the rotating strand being fed into it and then to put back the twist which it has taken out.

As the bunch rotating means can have a smaller radius of gyration and hence a higher permissible speed of rotation than that of the flyer of the bunching machine, which must be in excess of the radius of the take-up device, it is possible not only to obtain a technically satisfactory heavy fine wire strand which it is not possible to do on a double twist bunching machine alone, but to obtain it at a higher output speed than it would be obtainable by existing methods on a single twist bunching machine of the same maximum flyer speed of rotation.

The apparatus in accordance with the invention comprises a double twist bunching machine and input means for the machine capable of forming a bunch of wires and rotating the bunch about its axis at a speed greater than the speed of rotation of the flyer of the bunching machine.

The means for rotating the group of wires longitudinally advancing towards the flyer is preferably a haul-01f, for example of the endless belt type, which is bodily driven in rotation about an axis coincident with or approximating to the longitudinal axis of advance of the group of wires engaged by it, and/or the axis of the bunching machine associated with it.

An example of apparatus in accordance with the invention will be described with reference to the accompanying drawings in which FIGURE 1 is a partly diagrammatic elevation of the apparatus, partly in vertical section, and

FIGURE 2 is a plan of the apparatus.

Referring to the drawings, the apparatus comprises essentially a double twist bunching machine 1 of a conventional construction and an endless belt haulotf device 2 of conventional construction, both mounted for rotation about a common axis on a base 3, and means for forming a bunch of wires at the input end of the hauloff device. The apparatus shown in the drawings is capable, for example, of making a bunched strand from 216 copper wires of 0.018" diameter with the endless belt hauloff device 2 rotating about its axis at 800 rpm. and the flyer of the bunching machine 1 rotating about the same axis at 400 rpm.

The relative speeds of rotation of the axially rotating part of the input means, i.e. the endless belt haul-off device 2 in the drawings, and of the flyer of the bunching machine can be varied and the following table shows the effect of varying these relative speeds of rotation. In the table conditions (a) and (b) are outside and conditions (c), (d) and (e) are within the scope of the invention. Condition (f) is outside the scope of the invention unless, as described below, the take-up rotates in space.

The results obtained in condition (a) in which the hauloff is stationary and condition (b) in which the haul-off rotates at the same speed as the fiyer are equivalent to the results obtained in a normal double twist bunching machine and have the same disadvantage that, as the bunch is being twisted at the fiyer delivery, the wires will be subjected to uneven stress.

Condition (c) shows some improvement since A of the twist is imparted to the bunch while the wires can still be drawn off from the supply at different rates but the optimum condition is condition (d) when all of the required twist (two twists per unit length) is put into the bunch before it enters the bunching machine. Condition (e) is substantially equivalent to condition (c) and condition (f) to conditions (a) and (b). If the ratio were caused to rise above 3:1 the result would be worse than condition (a) or (b) unless the take-up of the bunching machine were caused to rotate in space in the opposite direction to the fiyer.

It will be seen that an axial counter rotation of the take-up equal in speed to the rotation of the fiyer would, in condition (f), cause two positive twists to be imparted to the bunch at the fiyer delivery end giving a final total of three twists per unit length, i.e. equal to the twist imparted by the haul-off device; although an improved bunch r strand would thus be obtained in accordance with the invention, there would be the attendant disadvantage that the heavy take-up, usually a drum, would have to be rotated in space about the machine axis.

TABLE Relative Twist per unit length imparted byspeeds of rotation of Flyer Flyer Condition haul-off: fiyer. Haul-oft entry delivery Total Referring again to the drawings, the copper wires 4 from which strand is made are drawn from stationary spools 5 through a number of apertured guide plates, shown diagrammatically as 6, and a die 7 by the continuous belt haul-01f device 2. The apertures in the guide plates 6 are arranged in rings of varying radius in such a way that the wires 4 do not become entangled in their approach to the die 7 the number of guide plates used varying in accordance with the number of wires.

The endless belt haul-0E device 2 and the bunching machine 1 are driven from an electric motor 8 through a comman shaft 9, in the following. way. The shaft 9 is coupled to a hollow shaft 10 on the input side of the hauloif device 2 through variable gearing mounted on the trunnion 11 and the upper and lower belts 12 and 13 of the haul-off device are driven through variable gearing mounted within the casing 14, forming part of the carriage of the haul-off device, and through a coupling shaft 15 and gearing 16 seen in FIGURE 2.

The fiyer of the bunching machine 1 comprises two end parts 17 and 18 mounted respectively on hollow shafts 19 and 20 driven at the same speed as each other, by toothed driving belts 21 and 22, from the common driving shaft. The trunnion 23 which is one of two trunnions by which the hollow shaft 19 is supported, also supports the delivery and of the haul-off device 2 in such a way that the haul-oil device can rotate about its axis at a different speed from the speed of rotation of the fiyer. Between the inner ends of the hollow shafts 19 and 20 a carriage for a take-up drum 24 is mounted in such a Way that it remains stationary in space as the fiyer rotates.

The take-up drum is driven from a pinion 25 on the hollow shaft 20 through a clutch 26, a shaft 27 and a train of pinions (see FIGURE 2) terminating with a pinion 28 mounted on the spindle 29 of the drum 24, provision being made for varying the take-up speed. The pinion 28 also drives a shaft 30 of a flaking gear for flaking the strand on to the drum 24.

The through-put speed of the apparatus can be varied up to 400 ft./minute and consequently the rotation of the haul-off device 2 at 800 r.p.m. twists the wires 4 brought together by the die 7 to form a bunch having a lay length of up to 6 inches as the wires pass between the belts 12 and 13. The bunch B thus formed passes through the hollow shaft 19 at the input end of the bunching machine, around guide pulleys 31 and 32 mounted in the part 17 of the fiyer, through a guide tube 33 interconnecting the two parts 17 and 18 of the fiyer on to a guide pulley 34 mounted on the part 18 of the fiyer. From the guide pulley 34, the bunch B passes around a further guide pulley 35 mounted in the part 18 of the fiyer, over a first roller guide (not shown) mounted between plates 36 and 37 and a second roller guide 38 on to a guide pulley 39 carried by the flaking gear. The bunch is shown passing onto the empty barrel 40 of the drum 24. When the drum is full it follows the chain-dotted path.

It will be appreciated that if the fiyer is rotated at 400 rpm. half of the twist put into the bunch of wires 4 by the haul-off device 2 is taken out of the bunch B at the input end of the bunching machine, i.e. before the bunch passes round the guide pulley 31, and that the same amount of twist is put back into the bunch B at the output end of the fiyer, after the bunch has left the guide pulley 35. The bunched strand taken up on the drum 34 therefore has a lay length equal to that of the bunch leaving the haul-off device.

As already described with reference to the table, the relative speeds of rotation of the fiyer and the haul-off device can be changed from the optimum ratio of 2:1 but if the ratio approaches or exceeds 3:1, it is necessary to cause the take-up drum 24 to rotate in space about the axis of the bunching machine.

What I claim as my invention is:

1. A method of forming a bunched strand of elongated flexible elements which comprises the steps of:

( a) bringing the elements together,

(b) forming the elements thus brought together into a twisted bunch by rotating the longitudinally advancing bunch about a rectilinear axis within the bunch, and

(c) feeding the rotating bunch thus formed into a double twist bunching machine whose fiyer is rotating in the same direction as but at a speed less than the speed of rotation of said rotating bunch such that a substantial proportion of but not substantially more than the twist in the finished strand taken-up in the bunching machine is put in prior to its entry into the bunching machine.

2. A method as claimed in claim 1 in which the takeup of the bunching machine remains stationary in space.

3. A method as claimed in claim 1 in which the relative speeds of rotation of said rotating bunch and of said flyer are such that the whole of the twist in the finished strand taken-up in the bunching machine is put in prior to its entry into the bunching machine.

4. A method as claimed in claim 1 in which said fiyer rotates at a speed substantially equal to half the speed of rotation of said rotating bunch and substantially all of the twist in the finished strand taken-up in the bunching machine is put in prior to its entry into the bunching machine.

5. A method as claimed in claim 1 in which the individual elements are drawn each from a separate stationary supply and brought together and formed into a twisted bunch by drawing means rotating about a rectilinear axis within the longitudinally advancing bunch, prior to feeding the rotating bunch thus formed into the double twist bunching machine.

6. A method as claimed in claim 5 in which the whole of the twist in the finished strand taken-up in the bunching machine is put in prior to its entry into the bunching machine.

7. A method as claimed in claim 5 in which the speed of rotation of said rotating bunch is substantially twice that of the flyer.

8. A method as claimed in claim 5 of forming a heavy fine wire strand in which said elements consist of at least one hundred fine wires.

9. Apparatus for forming a bunched strand of elongated fiexible elements which comprises:

(a) a double twist bunching machine comprising a flyer,

a take-up, and means for rotating the flyer around the take-up and relative thereto,

(b) input means therefor comprising means for bringing the elements together and forming them into a twisted bunch by rotating the longitudinally advancing bunch about a rectilinear axis within the bunch, and

(0) means coupling the input means to the flyer to rotate it in the same direction as but at a speed greater than the speed of rotation of the fiyer of the bunching machine.

10. Apparatus as claimed in claim 9 in which the means for bringing the elements together and forming them into a twisted bunch comprises a haul-off device 5 mounted for axial rotation to draw the elements from a stationary supply and feed them as a rotating bunch towards the bunching machine.

11. Apparatus as claimed in claim 10 in which the haul- 10 off device is of the endless belt type.

References Cited UNITED STATES PATENTS 776,509 12/1904 Good 5760 1,882,902 10/1932 Reichelt 5712 1,911,925 5/1933 Reed 5760 2,593,984 4/1952 Clary et a1. 5758.55 3,005,304 10/1961 Holm 5712 3,030,762 4/1962 Piz zi 5712 XR 20 3,091,074 5/1963 Dernmel 57 -12 3,388,543 6/1968 Downton 57166 XR 3,408,807 11/1968 Sylthe 5712 XR DONALD E. WATKINS, Primary Examiner D US. or. X.R. 

